Angle grind coating apparatus and a method thereof

ABSTRACT

An angle grind coating apparatus and method for providing a coating onto materials is described. The angle grind coating apparatus comprising workpiece holder (102) assembled for holding tool material (104) and is assembled over base (106) provided over a fixture (108). The workpiece holder (102) has a spring assembly (110) to apply an upward thrust force to the tool material (104) and a grinding wheel (114) is mounted perpendicular to the workpiece holder (102) to enable grinding of the tool material (104) fixed in front and just below the grinding wheel (114) to align the fixture (108) with the grinding wheel (114). The angle grind coating apparatus comprises an angle grinder (116) to enable rotation of the grinding wheel (114) over the tool material (104) at a predefined Rotations Per Minute (RPM), such that rotation of the grinding wheel (114) generates a stream of swarf particles (118) from the workpiece/tool material 104 and are deposited over a target surface fixed (120) at a pre-set standoff distance from the angle grind coating apparatus.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY

The present application claims benefit from Indian Pat. Application No.202111037717 filed on 19 Aug. 2021 the entirety of which is herebyincorporated by reference.

TECHNICAL FIELD

The present matter described herein, in general, relates to coatingapparatus. More particularly, the present subject matter relates to anangle grid coating apparatus.

BACKGROUND

Surface coating techniques are used to improve properties of a substratesuch as hardness, corrosion resistance, heat resistance surface porosityetc. Numerous methods can be used to coat a surface coating. The thermalspray technique is widely used to apply a coating onto a substratematerial. In the thermal spray technique, molten or semi-molten dropletsor particles of the coating material are sprayed onto the substratematerials.

The existing thermal spray coating techniques require a specializedthermal spray gun, a programable robot, and a spray booth workenvironment. Thus, the existing traditional technology of thermal sprayemploys expensive equipment and feedstock powders. The coating formed bythe thermal spray method has a relatively low adhesion strength;especially on small substrates and substrates of small curvature.Furthermore, using the thermal spray method applies a coating ofvariable materials quality and is not appropriate for forming coatingsonto hard substrates such as glass. Thus, there is a need for a coatingtechnique that are cost effective and technically viable for coatinghard materials that are difficult to surface prepare by the traditionalroughening methods

SUMMARY

Before the present angle grind coating apparatus and method thereof isdescribed, it is to be understood that this application is not limitedto a particular angle grind coating apparatus, as there may be multipleembodiments, which are not expressly illustrated in the presentdisclosure. It is also to be understood that the terminology used in thedescription is for the purpose of describing the particularimplementations, versions, or embodiments only, and is not intended tolimit the scope of the present application. This summary is provided tointroduce aspects related to an angle grind coating apparatus. Thissummary is not intended to identify essential features of the claimedsubject matter nor is it intended for use in determining or limiting thescope of the claimed subject matter.

In one aspect, an angle grind coating apparatus is disclosed. The anglegrind coating apparatus comprising a workpiece holder assembled forholding a tool material and the workpiece holder is assembled over abase provided with a stabilizing fixture. Further, the workpiece holderhas a tensioned spring to apply an upward thrust force to the toolmaterial. The angle grind coating apparatus further comprises a grindingwheel mounted perpendicular to the workpiece holder to enable grindingof the tool material. The tool material is fixed in front and just belowthe grinding wheel to align the fixture with the grinding wheel.Further, the angle grind coating apparatus comprises an angle grinder toenable rotation of the grinding wheel over the tool material at apredefined Rotations Per Minute (RPM), such that rotation of thegrinding wheel generates a stream of swarf particles from the toolmaterial. The stream of swarf particles is deposited over a targetsurface fixed at a pre-set standoff distance from the angle grindcoating apparatus.

In one aspect a method providing coating material is disclosed. Themethod comprises applying, through a spring, an upward thrust force overa tool material, and the tool material is fixed in a workpiece holder ofan angle grind angular coating apparatus. The workpiece holder furtheris assembled over a base provided over a fixture. The coating materialis provided by, grinding of the tool material that is mountedperpendicular to the workpiece holder. The tool material is fixed infront and just below of the grinding wheel aligning the fixture with thegrinding wheel. Furthermore, the method providing coating materialcomprises enabling, through an angle grinder, a rotation of the grindingwheel over the tool material at a predefined Rotations Per Minute (RPM),such that rotation of the grinding wheel generates a stream of swarfparticles from the tool material. The stream of swarf particles is to bedeposited over a target surface fixed at a pre-set standoff distancefrom the angle grind angular coating apparatus.

BRIEF DESCRIPTION OF DRAWING

The foregoing detailed description of embodiments is better understoodwhen read in conjunction with the appended drawings. For the purpose ofillustrating the present subject matter, an example of construction ofthe present subject matter is provided as figures; however, the presentsubject matter is not limited to the specific angle grind coatingapparatus and method thereof.

FIG. 1A shows a schematic of an angle grind coating apparatus, inaccordance with an embodiment of the present subject matter.

FIG. 1B and FIG. 1C shows line diagrams of the angle grind coatingapparatus, in accordance with an embodiment of the present subjectmatter.

FIG. 1D shows top view of the angle grind coating apparatus, inaccordance with an embodiment of the present subject matter.

FIG. 1E shows side view of the angle grind coating apparatus, inaccordance with an embodiment of the present subject matter.

FIG. 1F shows front view of the angle grind coating apparatus, inaccordance with an embodiment of the present subject matter.

FIG. 1G shows 3D view of the angle grind coating apparatus, inaccordance with an embodiment of the present subject matter.

FIG. 2A shows samples coated with low carbon steel swarf (metal) by theangle grind coating technology on glass substrate (1, 3), on analuminium substrate (2, 4, 6) and on an acrylic substrate (5); inaccordance with an embodiment of the present subject matter.

FIG. 2B shows a Scanning Electron Microscopy (SEM) analysis ofmicro-sized low carbon steel uncoated swarf produced during the anglegrind coating process, in accordance with an embodiment of the presentsubject.

FIG. 3 shows a schematic for powder production by means of the anglegrind coating apparatus, in accordance with an embodiment of the presentsubject matter.

FIG. 4 shows the cross-sectional SEM analysis of the low carbon steelswarf coating on aluminium (A), glass (B) and acrylic (C), in accordancewith an embodiment of the present subject matter.

FIG. 5 shows a method providing coating over a material, in accordancewith an embodiment of the present subject matter.

DETAILED DESCRIPTION

Some embodiments of this disclosure, illustrating all its features, willnow be discussed in detail. The words “comprising”, “including”,“containing”, “consisting”, and other forms thereof, are intended to beequivalent in meaning and be open ended in that an item or itemsfollowing any one of these words is not meant to be an exhaustivelisting of such item or items or meant to be limited to only the listeditem or items. It must also be noted that as used herein and in theappended claims, the singular forms “a,” “an,” and “the” include pluralreferences unless the context clearly dictates otherwise. Although anysystems and methods similar or equivalent to those described herein canbe used in the practice or testing of embodiments of the presentdisclosure, the exemplary angle grind coating apparatus and methodthereof is now described. The disclosed angle grind coating apparatusand method thereof are merely examples of the disclosure, which may beembodied in various forms.

Various modifications to the embodiment will be readily apparent tothose skilled in the art and the generic principles herein may beapplied to other embodiments. However, one of ordinary skill in the artwill readily recognize that the present disclosure for a process of anangle grind coating apparatus and method thereof is not intended to belimited to the embodiments illustrated but is to be accorded the widestscope consistent with the principles and features described herein.

The existing surface coating technologies such as thermal spraytechnologies may not be effective for coating ceramic surfaces such asglass, ceramics and acrylic. These surfaces are difficult to rougheneffectively. The present subject matter overcomes a problem of anefficient method for surface coating of such materials.

Referring now to FIGS. 1A-1G in combination, an angle grind coatingapparatus 100, in accordance with an embodiment of the present subjectmatter may be described. The angle grind coating apparatus 100 comprisesa workpiece holder 102 assembled for holding a tool material 104. Thetool material (workpiece) 104 may be a cylindrical tool material(workpiece) 104 containing a low carbon steel. The work piece holder 102may further be assembled over a base 106 provided over a fixture (108)and comprises a spring assembly 110 to apply an upward thrust force tothe tool material (workpiece) 104. The spring (112) may have a springconstant in the range 0.45 N/mm to 0.55 N/mm.

In an embodiment, the angle grind coating apparatus 100 comprises agrinding wheel 114 mounted perpendicular to the workpiece holder 102 forenabling grinding of the tool material (workpiece) 104. The toolmaterial (workpiece) 104 may be fixed in front of the grinding wheel 114and just below the grinding wheel 114 to align the fixture 108 with thegrinding wheel 114. Further, the grinding of the tool material(workpiece) 104 may be controlled by adjusting at least one of a springstiffness, alignment of the fixture 108, and rotational speed of thegrinding wheel 114. Further, a safety plate 122 may be located on top ofthe grinding wheel 114.

In an embodiment, the angle grind coating apparatus 100 furthercomprises an angle grinder 116 that may enable rotation of the grindingwheel 114 over the tool material (workpiece) 104 at a predefinedRotations Per Minute (rpm). The RPM of the grinding wheel 114 may be ina range of operation up to 10,000 RPM.

In an embodiment rotation of the grinding wheel 114 may generate amicrometre sized stream of swarf particles 118 from the tool material(workpiece) 104. The generated stream of swarf particles 118 may bedeposited over the target surface fixed 120 at a pre-set stand-offdistance from the angle grind coating apparatus 100. The target surfacemay be selected from one of a metal substrate, a polymer substrate or aceramic substrate. The coating of the stream of swarf particles 118 maybe controlled by adjusting the stand-off distance and impact angle ofthe stream of swarf particles 118 generated due to grinding. The swarfparticles deposited 130 may have shape comprising spherical, needle orplatelet morphology. The shape of swarf particles deposited 130 maydepend on a set of grinding variables.

In an embodiment the set of grinding variables comprises stand-offdistance between the work piece 104 and the substrate, rotational speedof angle grinding disk, spring stiffness of the spring in the infeedholder, feed rate of tool material (workpiece) 104, flow rate of theswarf particles 128, and trajectory of a swarf particles stream.

In an embodiment, the angle grind coating apparatus 100 furthercomprises a handle 124 provided over the angle grinder for holding theapparatus. The angle grind coating apparatus further comprises a links126 connected to each of the fixture 108 and the angle grinder. Thelinks 126 are provided for the assembly of the cylindrical shapedworkpiece holder 102, spring 110 and the base plate 106 to fixture 108.The links 126 may hold the assembly together and position at a properlocation.

FIG. 1B shows photographs of the angle grind coating apparatus 100. Topview, side view and front view of the angle grind coating apparatus 100may be seen from FIG. 1 .

Table 1 Grinding variables for different substrates Sr. No. Type ofdeposited material Tool material (Workpiece) Substrate materialStand-off distance range (mm) Abrasive cutter speed (rpm) 1 Metal Lowcarbon steel swarf Aluminium 70-320 10,000 2 Metal Low carbon steelswarf Acrylic 100-350 10,000 3 Metal Low carbon steel swarf Glass100-300 10,000

Now referring to Table 1, a set of grinding variables for differentsubstrates such as aluminium, acrylic and glass is shown. As observedfrom the table 1, the stand-off distance is lower for aluminium and thestand-off distance is higher for glass. However, the rotation of thespeed for these examples is maintained constant for all the substrates,although the RPM can also be a variable. The swarf particles 128 aredeposited onto the substrate surface at a high impact speed and elevatedtemperature. In the process of coating, the temperature of the substrateat the start of the process is maintained at room temperature and thetemperature of the substrate increases due to the impact of the swarfparticles 128 that may be removed from the tool material (workpiece)104. The increase in temperature during the coating process isproportional to the grinding time and the process variables.

In an example embodiment, heated swarf particle from low carbon steel,formed by the angle grind coating apparatus 100 may be achieved bycontrolling the operating parameters as mentioned in Table 1. Thesubstrate used for coating may comprise one of a metal or a non-metal.The coating thickness may be achieved by repeated passing of the swarfparticles 128 across the substrate. The angle grind coating apparatus100, which may also be operated in a manual or robot-controlled fashion,deposits coating on contoured materials since it can be angled in manydirections due to high versatility derived from a small equipmentprofile.

Now referring to FIG. 2A, coating of low carbon steel swarf on glass (1,3), aluminium (2, 4 and 6) and acrylic (5) is illustrated. FIG. 2Billustrates cross-sectional Scanning Electron Microscope (SEM) analysisof the low carbon steel swarf coating on aluminium (A), glass (B) andacrylic (C). Coating on different surfaces may be achieved by placingthe substrate at different standoff distances. Coating of low carbonsteel on the aluminium substrate may be achieved at the standoffdistance in the range of 70 mm to 320 mm. Metal coating on the glasssubstrate may be achieved using angle grind coating apparatus 100. Thecoating on the glass substrate may be achieved at the standoff distanceof 190 mm. Further, metal coating on an acrylic polymer substrate at isachieved at the standoff distance in the range of 100 mm to 350 mm.

Referring to FIG. 3 and FIG. 4 , in another exemplary embodiment, theangle grind coating apparatus 100 may be used for powder generation bysegregation and separation swarf particles 128 from the stream of swarfparticles during angle grind coating process when the stand-off distanceis greater than 400 mm. For powder generation, a container 302 may beplaced in front of the stream of swarf 118. The swarf particles 128formed may have varying shape and size. The swarf particles 128 may havespherical 304 or non-spherical shapes 306. The shape and size of swarfscrap may be segregated by magnetic and mechanical scrap separators 308.The segregated swarf particles 128 are cleaned 314. Spherical 304 andnon-spherical 306 swarf particles 128 are detected during SEM analysisas shown in FIG. 4 . Further, the process parameters of the angle grindcoating apparatus 100 may control the shape and size of the swarfparticle. The segregated and cleaned spherical swarf particles 304 maybe used as a feedstock 316 for material coating technique such asthermal spray, cold spray, plasma spray, additive manufacturing, powdermetallurgy and technology that require bespoke powder.

Referring now to FIG. 5 , a method 500 providing coating over thematerial is illustrated in accordance with the present embodiment. Themethod may be executed through the angle grind coating apparatus 100.

At block 502, the upward thrust force over the tool material (workpiece)104 fixed in the workpiece holder 102 of the angle grid coatingapparatus 100 may be applied through the spring assembled 110.

At block 504, the grinding of the tool material (workpiece) 104 may beenabled through the grinding wheel 114 mounted perpendicular to theworkpiece holder 102.

At block 506, the rotation of the grinding wheel 114 over the toolmaterial (workpiece) 104 at the predefined Rotation Per Minute (RPM) maybe enabled though the angle grinder.

Details of the method 500 are similar to details of the angle grindcoating apparatus 100 and hence are not repeated for the sake ofbrevity.

Exemplary embodiments discussed above may provide certain advantages.Though not required to practice aspects of the disclosure, theseadvantages may include those provided by the following features.

Some embodiments of angle grind coating apparatus 100 may provide thecost-effective method 500 for substrate coating.

Some embodiments of angle grind coating apparatus 100 may enable coatingon to metal, polymer, and ceramic surfaces; or a surface that is acombination of these materials.

Some embodiments of the angle grind coating apparatus 100 may provide aportable equipment that may be lightweight and compact in size.

1. An angle grind coating apparatus (100), comprising: a workpieceholder (102) assembled for holding a tool material (104), wherein theworkpiece holder (102) is assembled over a base (106) provided over afixture (108), wherein the workpiece holder (102) has a spring assembly(110) to apply an upward thrust force to the tool material (104); agrinding wheel (114) mounted perpendicular to the workpiece holder (102)for enabling grinding of the tool material (104), wherein the toolmaterial (104) is fixed in front and just below the grinding wheel (114)to align the fixture 108 with the grinding wheel (114); and an anglegrinder (116) to enable rotation of the grinding wheel (114) over thetool material (104) at a predefined Rotations Per Minute (RPM), suchthat rotation of the grinding wheel (114) generates a stream of swarfparticles (118) from the tool material (104), wherein the stream ofswarf particles (118) is deposited over a target surface fixed (120) ata pre-set standoff distance from the angle grind coating apparatus. 2.The angle grind coating apparatus as claimed in claim 1, wherein thetool material 104 comprises a cylindrical workpiece (104), wherein thecylindrical tool material (104) comprises low carbon steel.
 3. The anglegrind coating apparatus as claimed in claim 1, comprising: a safetyplate (122) located on top of the grinding wheel (114).
 4. The anglegrind coating apparatus as claimed in claim 1, wherein the stream ofswarf particles (118) comprises swarf particles 128 in micrometer size.5. The angle grind coating apparatus as claimed in claim 1, wherein thetarget surface comprises a substrate selected as one of a metalsubstrate, a polymer substrate or a ceramic substrate.
 6. The anglegrind coating apparatus as claimed in claim 1, wherein the RPM comprisesin a range of operation up to 10,000 rpm.
 7. The angle grind coatingapparatus as claimed in claim 1, wherein the grinding of the toolmaterial (104) is controlled by adjusting at least one of a springstiffness, alignment of the fixture (108), and rotational speed of thegrinding wheel (114).
 8. The angle grind coating apparatus as claimed inclaim 1, comprising: a handle (124) provided over the angle grinder forholding the apparatus.
 9. The angle grind coating apparatus as claimedin claim 1, comprising: links (126) connected to each of the fixture(108) and the angle grinder, the links (126) are provided for theassembly of the cylindrical shaped workpiece holder (102), spring (112)and base plate (106) of fixture (108).
 10. The angle grind coatingapparatus as claimed in claim 1, wherein the coating of the stream ofswarf particles (118) is controlled by adjusting the stand-off distanceand impact angle of the stream of swarf particles (118) generated due togrinding.
 11. The angle grind coating apparatus as claimed in claim 1,wherein swarf particles (118) of shape comprising spherical, needle orplatelet morphology are deposited; and wherein the shape is based on aset of grinding variables.
 12. The angle grind coating apparatus asclaimed in claim 4, wherein the set of grinding variables comprisesstand-off distance between the tool material (104) and the substrate(120), rotational speed of angle grinding disk, spring stiffness of thespring (112) in the infeed holder, feed rate of tool material, flow rateof the swarf particles 128, and trajectory of a swarf particles stream.13. A method providing coating over a material, the method comprising:applying, through a spring (112), an upward thrust force over a toolmaterial (104), wherein the tool material (104) is fixed in a workpieceholder (102) of an angle grind coating apparatus, wherein the workpieceholder (102) is assembled over a base (106) provided over a fixture(108); enabling, through a grinding wheel (114), grinding of the toolmaterial (104), wherein the grinding wheel (114) is mountedperpendicular to the workpiece holder (102), wherein the tool material(104) is fixed in front and just below of the grinding wheel (114)aligning the fixture (108) with the grinding wheel (114); and enabling,through a tool material (104), a rotation of the grinding wheel (114)over the tool material (104) at a predefined Rotations Per Minute (RPM),such that rotation of the grinding wheel (114) generates a stream ofswarf particles (118) from the tool material (104), wherein the streamof swarf particles (118) is to be deposited over a target surface fixed(120) at a pre-set standoff distance from the angle grind coatingapparatus.
 14. The method as claimed in claim 13, wherein the RPMcomprises in a range of operation up to 10,000 rpm.
 15. The method asclaimed in claim 13, wherein the grinding of the tool material (104) iscontrolled by adjusting at least one of a spring stiffness, alignment ofthe fixture (108), and rotational speed of the grinding wheel (114). 16.The method as claimed in claim 10, wherein grinding is controlled bycontrolling at least one of a stand-off distance and impact angle of thestream of swarf particle (118) is adjusted and varied manually.
 17. Themethod as claimed in claim 11, wherein swarf particles (128) of shapecomprising spherical, needle or platelet are deposited; and wherein theshape is based on a set of grinding variables.
 18. The method as claimedin claim 13, wherein the set of grinding variables comprises stand-offdistance between the work piece used as a tool material (104) and thesubstrate, rotational speed of angle grinding disc, spring stiffness ofthe spring (112) in the infeed holder, feed rate of tool material (104),flow rate of swarf particles 128, and trajectory of the swarf particlestream.